ScuzzBlog: Diaries March 2022
Entry 24th March 2022: Post 1: Amiga 500 - On the Plus side still working.
Amiga 500 - On the Plus side still working.
Some of my Amiga projects have been a long hard struggle. This little
baby has been to hell and back and still manages to make me smile.
On the face of it she looks like an A500 Plus, but this disguises
a different story... for she is really an A500. She thinks she is
an A500 Plus... so let's not ruin things for her.
On 5th January 2008 I acquired a busted A500 motherboard just for
the chips and stuff. I had no idea what was wrong with the board.
About the same time I received a broken A500 Plus computer which
was way too far gone to try and recover. This computer I managed
to lock away so deep in the store I forgot completely about it.
Fast forward to November 2017 and I was sick of kicking this old
A500 motherboard around the store and decided I would make good
use of it. At the same time I featured the busted A500 Plus and
determined I would use the A500 in the Plus case.
So what were the immediate issues... Let me see. Busted floppy
drive, broken keyboard, not booting. I got started with the
problems and found a bent pin on the CPU, so fixed that. Next I
used an old Amiga 2000 floppy drive and got that working. I had
to disassemble and change the support bracket to suit.
Next up the GARY had popped and so I replaced that. Finally I
couldn't get the mouse to click icons and discovered a fault with
the DENISE. This was replaced with the ECS version. I swapped the
1.3 ROM for a 2.04 ROM and so the computer was now full ECS. She
already had the 1MB AGNUS as she was a revision 6A motherboard.
I then fitted a 512K RM550C RAM card with a nifty little switch
and in truth I thought all was working. I typed a full statement
in on the SHELL and all the writing appeared OK. First though I
did have to remove the leaking battery off the RAM card.
WRONG !!!
I had failed to read my first note on the trapdoor about the prob
with the keyboard. I was missing '- [ # and the RETURN'. These are
in a line and point to a busted trace. So I need another keyboard
or mend the broken trace. Not a today job.
Anyhoo ... I did my usual photo-shoot of taking the A500 apart blah
blah .. You all know the drill on how I do this. I amended the
label to add back the busted keyboard note and placed her back in
store until I get round to making the repair. You will note that
the computer is No 20 previously 6. I was moving A500 number 37
today so you will appreciate I have no shortage of A500/A500 Plus
machines. So not a today problem.
Did you know that with the 2.04 ROM came resident AmigaDOS commands
that instead of being software based are actually on the ROM. Just
type RESIDENT in the SHELL and you will see what is on the ROM.
Amiga 500 - On the Plus side still working.
|
